During the COVID-19 pandemic, healthcare workers (HW) have faced an extremely difficult work environment, with an increased workload and traumatic events. Our study aimed to investigate the impact of COVID-19 pandemic on HW’s mental wellbeing. We analyzed the correlations between levels of burnout and other mental health disorders and we searched for the presence of specific risk factors of post-traumatic symptomatology related to the pandemic. A structured an on-line questionnaire and validated instruments were completed by a sample of HW from some hospitals in Genoa, Italy. Anxious, depressive, post-traumatic and other psychological symptoms were assessed and risk factors, related to the pandemic, were considered. Then, we investigated the correlation between levels of burnout and the risk of developing psychopathology. A total of 731 HW were screened, and we found increased levels of anxiety (61%), depression (62%), PTSD (34%) and high levels of burnout; especially emotional exhaustion (37%). A statistically significant association between burnout and insomnia, depression, anxiety, and post-traumatic symptoms was demonstrated. This study indicates that during the COVID-19 pandemic, HW showed high levels of psychological distress and that burnout is an important predictor of sufferance. These findings support the idea to provide psychological and psychiatric support for HW.